Growth mechanisms of interstitial loops in α-doped UO2 samples

New experimental size distributions are presented for interstitial-type dislocation loops in (U, Pu)O2 samples after 4 and 7 years of self-irradiation along with a new model. For this model, the work of Hayns has been extended to doped materials and to take into account additional phenomena, namely re-solution and coalescence as applied to gas bubble precipitation. The calculations are compared to the experimental size distributions obtained by means of Transmission Electron Microscopy for two different storage times. The role of re-solution and coalescence is discussed based on this model. This constitutes a basis for modelling the high burn-up structure (HBS) formation which is a consequence of the accumulation of radiation damage in nuclear fuels.